Since penicillin was firstly used clinically in 1940s, it had been known as a miracle medicine saving many lives against infectious diseases. However, it was not long till Staphylococcus aureus having resistance against penicillin appeared. In 1960s, methicillin, semi-synthetic penicillin, was developed and used to treat infectious diseases caused by penicillin-resistant Staphylococcus aureus, and in 1973, cefazolin was developed. But, methicillin-resistant Staphylococcus aureus (MRSA) and cefazolin-resistant strain appeared, and a number of antibiotics including cephalosporin, quinolone, carbapenem, monobactam and glycoside have been developed to deal with the resistant bacteria. However, penicillin-resistant Streptococcus pneumococcus, MRSA and other antibiotics-resistant bacteria continued to cast problems over the world.
Therefore, there has been a continual need to develop still new antibiotics having antibacterial activity against not only Gram-positive and Gram-negative bacteria but also resistant bacteria. Recently, it was reported that 2-arylcarbapenem compounds (L-695256 and L-742728, MERCK) showed good activity against MRSA, VRSA and VRE (Hugh rosen et al., Sciences, 703(1999)). WO 99/62906 reports that 2-benzothiazolethenyl carbapenem has good activity against MRSA. In addition, many antibiotics derived from carbapenem have been reported to show some activity against MRSA. For example, imipenem and meropenem are effective in treating infection by MRSA having weak resistance.
Accordingly, the present inventors have endeavored to develop an antibiotic having a wide spectrum of antibacterial activities against Gram-positive and Gram-negative bacteria, which can be used to treat infection by resistant bacteria such as MRSA.